| % Generated by roxygen2: do not edit by hand |
| % Please edit documentation in R/parquet.R |
| \docType{class} |
| \name{ParquetWriterProperties} |
| \alias{ParquetWriterProperties} |
| \title{ParquetWriterProperties class} |
| \description{ |
| This class holds settings to control how a Parquet file is read |
| by \link{ParquetFileWriter}. |
| } |
| \details{ |
| The parameters \code{compression}, \code{compression_level}, \code{use_dictionary} |
| and write_statistics` support various patterns: |
| \itemize{ |
| \item The default \code{NULL} leaves the parameter unspecified, and the C++ library |
| uses an appropriate default for each column (defaults listed above) |
| \item A single, unnamed, value (e.g. a single string for \code{compression}) applies to all columns |
| \item An unnamed vector, of the same size as the number of columns, to specify a |
| value for each column, in positional order |
| \item A named vector, to specify the value for the named columns, the default |
| value for the setting is used when not supplied |
| } |
| |
| Unlike the high-level \link{write_parquet}, \code{ParquetWriterProperties} arguments |
| use the C++ defaults. Currently this means "uncompressed" rather than |
| "snappy" for the \code{compression} argument. |
| } |
| \section{Factory}{ |
| |
| |
| The \code{ParquetWriterProperties$create()} factory method instantiates the object |
| and takes the following arguments: |
| \itemize{ |
| \item \code{table}: table to write (required) |
| \item \code{version}: Parquet version, "1.0" or "2.0". Default "1.0" |
| \item \code{compression}: Compression type, algorithm \code{"uncompressed"} |
| \item \code{compression_level}: Compression level; meaning depends on compression algorithm |
| \item \code{use_dictionary}: Specify if we should use dictionary encoding. Default \code{TRUE} |
| \item \code{write_statistics}: Specify if we should write statistics. Default \code{TRUE} |
| \item \code{data_page_size}: Set a target threshold for the approximate encoded |
| size of data pages within a column chunk (in bytes). Default 1 MiB. |
| } |
| } |
| |
| \seealso{ |
| \link{write_parquet} |
| } |